1. Field of the Invention
The present invention relates generally to the medical arts, and particularly to a class of medical devices commonly referred to as oral airways which are inserted into the pharynx of a patient through the mouth while the patient is under anesthesia or is undertaking respiratory treatment.
2. Description of the Prior Art
While a surgery patient is under a general anesthesia, it is absolutely essential to maintain an unobstructed airway for the patient. Present commercially available oral airways are relatively rigid, and require about 15 different sizes to fit the variety of airway sizes that the anesthesiologist encounters. These multiple sizes often make it difficult to find an airway size that best fits the patient's particular airway dimensions. Further, it is a frequent occurrence after insertion of present commercially available airways that hypoxia is encountered after induction.
Gereg, in U.S. Pat. No. 4,498,473, discloses an inflatable tracheal tube which is rendered relatively stiff during insertion, and which thereafter may have a portion of the inflating fluid withdrawn to render the tube more flexible when in place. In U.S. Pat. No. 2,599,521, Berman discloses an H-shaped oral airway fabricated from a relatively soft elastomer so as to avoid the patient trauma caused by the hard rubber or metal oral airways that were in use prior to his development. A similar disclosure is made by Elmore in U.S. Pat. No. 2,705,959, wherein the material from which an oral airway is fabricated is semi-flexible. In U.S. Pat. No. 3,419,004, Berman also discloses an oral airway fabricated from a soft elastomer into a generally X configuration, and with a telescoping bite block.
In U.S. Pat. No. 3,930,507, Berman discloses an adjustable oral airway having a superior section and an inferior section joined by a hinge, and slideably secured together at the mouthpiece end by a tongue and groove slideable joint. The space between the two sections may then be adjusted by sliding the upper and lower sections of the mouthpiece, in order to expand or reduce the pharynx or lift the epiglottis.
Other prior art of interest includes the following U.S. Pat. Nos.: 2,099,127 to Leech; 3,306,298 to Raimo; 3,576,187 to Oddera; 3,756,244 to Kinnear et al; 3,908,665 to Moses; 3,926,196 to Bornhorst et al; 4,033,353 to LaRosa; 4,054,135 to Berman; 4,112,936 to Blachly; 4,148,308 to Sayer; 4,198,970 to Luomanen; and 4,270,531 to Blachly.